1. Field of the Invention
The present invention relates to medical devices and, more particularly, to methods and apparatus for sacroiliac joint stabilization.
2. Description of the Related Art
The sacroiliac joint is the joint between the sacrum and the ilium of the pelvis. Strong ligaments connect the sacrum to the ilium. The sacrum supports the spine and is supported on each side by an ilium. The sacroiliac joint is a synovial joint with cartilage and irregular elevations and depressions that produce interlocking of the two bones.
Pain in the sacroiliac joint can be caused by a number of conditions, including fracture or dislocation of the pelvis, degenerative arthritis, sacroiliitis (inflammation of the sacroiliac joint), or osteitis condensans ilii. One method for treatment of sacroiliac joint dysfunction is fusion of the sacroiliac joint. Fusion can be accomplished in a number of ways, for example an anterior approach, a posterior approach, or percutaneous screw fixation. The anterior approach can involve an incision along the iliac crest to the anterior superior iliac spine, followed by stripping the iliacus muscle to gain access to the sacroiliac joint. This approach poses a danger of damaging the L5 nerve root which is positioned near the sacroiliac joint. The posterior approach can use any of a number of different incisions, followed by stripping the gluteus maximus off the ilium to gain access to the joint. Both the anterior and posterior approaches pose risk of infection, and require relatively large incisions, resulting in unsightly scarring.
Percutaneous sacroiliac joint fusion can reduce the size of necessary incisions and lower the risk of infection through the minimally invasive introduction of joint fixation elements. Such methods typically include various fixation systems that are used for the stabilization of the sacroiliac joint. These fixation systems may include a variety of longitudinal elements such as screws which span the sacroiliac joint and are affixed to the sacrum through the ilium. These systems may be affixed to one side of the patient or to both sides.
Notwithstanding the variety of efforts in the prior art, there remains a need for a fixation device for sacroiliac joint stabilization with improved locking force, which resists migration and rotation, and which can be easily and rapidly deployed.